SM6453AB_02 Datasheet, PDF (14/19 Pages) Nippon Precision Circuits Inc – 3-wire Serial Data Volume Control for Headphone Amplifier IC

SM6453AB
I Example 3
C₁ = 0.1µF, C₂ = 0.047µF, C_IN = 1µF, C_OUT = 220µF, R_OUT = 16Ω
15
10
5
0
-5
-10
-15
10
BB2
BB1
BB OFF
100
1000
Frequency [Hz]
10000
I Example 4
C₁ = 0.22µF, C₂ = 6800pF, C_IN = 0.47µF, C_OUT = 47µF, R_OUT = 16Ω, 2700Ω resistor connected between
BSTN and VREF1
Note that when the output coupling capacitance C_OUT is small, the bass signal component margin available
before reaching the bass output saturation level is considerably reduced.
15
10
5
0
–5
–10
–15
–20
–25
–30
–35
10
BB2
BB1
BB OFF
100
1000
Frequency [Hz]
10000
Automatic gain control (AGC) function
The AGC function is selected using bit D11. When bass boost is on, whenever the magnitude of either the pos-
itive or negative output voltage peak value of LOUT or ROUT exceeds VREF1 + 0.48V (typ), half-wave recti-
fication starts. The resulting detected and smoothed DC potential is compared with the VREF1 potential, and
the comparator output signal is used to control the reduction in bass boost gain, thereby increasing the head-
phone amplifier output bass clip margin.
NIPPON PRECISION CIRCUITS INC.—14